1. The Field of the Invention
The present application relates to the field of optical communications. More particularly, the present invention relates to methods and devices for actively aligning optical components such as lasers and photodiodes.
2. The Relevant Technology
Computer and data communications networks continue to develop and expand due to declining costs, improved performance of computer and networking equipment, the remarkable growth of the internet, and the resulting increased demand for communication bandwidth. Such increased demand is occurring both within and between metropolitan areas as well as within communications networks. Moreover, as organizations have recognized the economic benefits of using communications is networks, network applications such as electronic mail, voice and data transfer, host access, and shared and distributed databases are increasingly used as a means to increase user productivity. This increased demand, together with the growing number of distributed computing resources, has resulted in a rapid expansion of the number of fiber optic systems required.
Through fiber optics, digital data in the form of light signals is formed by light emitting diodes or lasers and then propagated through a fiber optic cable. Such light signals allow for high data transmission rates and high bandwidth capabilities. Other advantages of using light signals for data transmission include their resistance to electromagnetic radiation that interferes with electrical signals; fiber optic cables' ability to prevent light signals from escaping, as can occur electrical signals in wire-based systems; and light signals' ability to be transmitted over great distances without the signal loss typically associated with electrical signals on copper wire.
Optical devices are commonly packaged as part of an assembly of mechanical, electrical, and optical components designed to couple light into, or receive light from, other optical elements. As one example, an individual optical device may be packaged to couple light into, or receive light from, a single optical fiber. Such optical devices, such as lasers, lenses, and photodiodes that are optically coupled to other devices or waveguides typically need to be suitably aligned so as to effectively pass an optical signal between the various devices.
Particularly, a laser is a light source that produces, through stimulated emission, coherent, near monochromatic light. The emitted laser light can be As HLL modulated to provide optical signals that can be transmitted over great distances. In this manner, an electrical signal is converted to an optical signal for data transmission. The optical signal is, in turn, received and converted back to an electrical signal by a receiver such as a monitor photodiode. A transceiver is an optical device that includes both a laser (as part of a transmitter) and a photodiode (as part of a receiver).
Proper device alignment is important to the operation of both lasers and photodiodes. One conventional method of assembling a laser or photodiode in a larger device involves aligning a laser to a housing/lens assembly with extreme accuracy and then gluing or otherwise securing the parts in place. The alignment must be active, meaning the laser or photodiode is powered up so that the signal is generated or measured. Current methods for holding the laser or photodiode leads to power up the laser produce excessive drag on the laser leads upon extraction of the completed assembly. This drag on the leads causes misalignment of the parts, often because the adhesive is not completely cured. Such problems lead to up to a 5% failure rate in manufacturing.
Accordingly, what is needed are quick, reliable methods of holding laser or photodiode leads for active alignment without damaging the leads.